[RPG] Battle Master fighter’s Trip Attack when the target is already dead from the regular hit


The Battle Master fighter has the Trip Attack maneuver (PHB, p. 74):

When you hit a creature with a weapon attack, you can expend one superiority die to attempt to knock the target down. You add the superiority die to the attack’s damage roll, and if the target is Large or smaller, it must make a Strength saving throw. On a failed save, you knock the target prone.

By R.A.W., you wait to see if the attack hits before rolling the superiority die for Trip Attack.

Is there a rule which demands that the DM resolve the damage and determine whether the target is dead, before a player ends up wasting their superiority dice on a pointless maneuver?

Best Answer

Not dead yet

As you've quoted, the Maneuver is added on the hit and then you add the superiority die to the damage and resolve the save.

Damage hasn't yet been rolled, so you don't know if the regular hit killed a creature.

This does mean that you may expend the resource with no additional gain.